The present invention relates to the regasification or vaporization of normally gaseous fluids in liquefied state and more particularly to the use of solar energy for such vaporization.
Natural gas, for example, often is available in areas remote from where it ultimately will be used. Often, shipment of such natural gas involves marine transportation which makes it desirable to bulk transfer the natural gas by liquefying the natural gas so as to greatly reduce its volume for transportation at essentially atmospheric pressure. Under these conditions, the liquefied natural gas (hereinafter referred to as LNG) is at a temperature of approximately -162.degree. C., though heavier hydrocarbons (such as, for example, ethane, propane, butane, and the like) often vary the boiling point range of the LNG to between about -133.degree. and -168.degree. C. Heretofore, a wide variety of heat transfer fluids have been proposed for the regasification or vaporization of LNG. Such heat transfer fluids include air (U.S. Pat. No. 3,978,663), ambient water (U.S. Pat. Nos. 3,726,101; 3,726,085; and 3,720,057), distillate from hydrocarbon distillation columns (U.S. Pat. No. 3,452,548), sea water often in conjunction with a desalinization process (U.S. Pat. Nos. 3,724,229; 3,892,102; and 3,892,103), and like fluids. It even has been proposed to vaporize liquid chlorine with ambient water (U.S. Pat. No. 1,588,699).
In all of the foregoing prior art proposals, the heat transfer fluid can be at ambient temperature, be heated by conventional fuel fired heaters, be heated by turbine exhaust gas and the like. However, the application of solar energy for the regasification of normally gaseous fluids in liquefied state has not been advocated in the art, nor has an efficient and economic solar energy system for such regasification been proposed.